1. Field of the Invention
The present invention relates to package structures and fabrication methods thereof, and more particularly, to a package structure and a fabrication method thereof having reduced processes.
2. Description of Related Art
Along with the rapid development of electronic industries, electronic products are required to be much lighter, thinner, shorter and smaller and multi-functional. Accordingly, there have been developed various types of semiconductor packages. In particular, PoP (Package on Package) technologies have been developed to meet the requirement of semiconductor devices for high performance, high power efficiency, high speed, high integration and small size.
FIGS. 1A and 1B are schematic cross-sectional views showing a method for fabricating a PoP structure according to the prior art.
Referring to FIG. 1A, a carrier 10 having a plurality of conductive pads 101 and a plurality of conductive vias 102 is provided. Then, an electronic element 11 having a plurality of electrode pads 110 is disposed on the carrier 10 and electrically connected to the conductive vias 102 through the electrode pads 110. Subsequently, an encapsulant 12 is formed to encapsulate the electronic element 11 and the conductive pads 101. Thereafter, a grinding process is performed on the encapsulant 12 to expose a surface of the electronic element 11 from the encapsulant 12.
Referring to FIG. 1B, a plurality of openings 121 are formed in the encapsulant 12 by laser ablation for exposing the conductive pads 101. Subsequently, a plurality of conductive elements (not shown) are formed in the openings 121 of the encapsulant 12. As such, a package can be stacked on and electrically connected to the conductive pads 101, thereby forming a PoP structure.
However, since the conductive pads 101 are encapsulated by the non-transparent encapsulant 12, the positions of the conductive pads 101 are difficult to be identified and consequently the openings 121 are usually formed with a positional deviation.
Further, when the openings 121 are formed by laser ablation, debris is easily generated near the openings 121 and needs to be cleaned through a cleaning process, thereby complicating the fabrication process. Furthermore, the cleaning process causes sidewalls of the openings 121 to become uneven. Therefore, a delamination easily occurs between the openings 121 and the conductive elements formed in the openings 121 and consequently the product reliability is reduced. In addition, since the openings 121 need to be formed one by one by the laser ablation process and a laser ablation device is quite expensive, both the fabrication time and cost are increased.
Therefore, how to overcome the above-described drawbacks has become critical.